Railway traffic controlling apparatus



0st. 27, 1942. H. s. YOUNG I 2,300,272

RAILWAY TRAFFIC coN'TRoLLING APPARATUS Filed Decmzsl.' 1959 7 sheets-snaai 1 g5 A'Ar'roRNEY l 5M l #5613 w 5291A.

RAILWAY TRAFFIC CONTROLIJING APPARATUS ,Filed De. 25, 1959 7 sheets-sheet s ."fr@ l? m: .rlf

I I l fn" l ,l l 7B: 122'? INVENTOR H9121 Yeung. BY

H5' ATTORNEY Oct. 27, 1942, H. s. YOUNG RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 23, 1959 7 Sheets-Sheet 4 E 101 411 E @im i l I MAS IZIZP A C I B INVENTOR Hezzffg/ Yuzzg.

H15 ArroRNEY c C1245 7%] JIZaI Oct. 27, 1942. H. s. YOUNG 2,300,272

RAILWAY TRAFFIC CONTROLLIING APPARATUS Filed 1396.23, 1939 '7 sheets-snaai 5 Fly". IH.

y I INVENToR Helm .I/zzng.

HIS ATTORNEY,

Oct. 27, 1942. H. s. YQUNG 2,300,272

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 23; 1959 V'r sheets-snaai e ILS [LS im l gg, B VUT 192 l 95 V lp. lf2@ ifi 15H C iNvENToR I I B'Y HIS ATTORNEY Oct. 27, 1942. v H, s, YQUNG 2,300,272

RAILWAY TRAFFIC CONTROLLING APPARATUS- Filed Dec'. 25, 1939 7 Sheets-Sheet '7 l c 550;@ 516';- V E 10E VZW? 4AS A122? ,mls 7W; 72' 12,45 B97 145 C C l .-J 5 A 4W E 12E 206 A] @i f IVENTOR Henry Iba/2g. a-Y

H16' ATTORNEY Patented Oct. 27, 1942 UNE'E'ED STATES Y RAILWAY TRAFFIC CONTROLLING APPARATUS Application December 23, 1939, Serial No. 310,798

28 Claims.

My invention relates to railway traic controlling apparatus, and more particularly to an interlocking control system for governing the movement of traffic through a track layout comprising a plurality of track sections interconnected by track switches which may be variously arranged to form different tralic routes.

The system of my invention is of the route interlocking type, in which the switches and signals for the dierent traiiic routes are governed by momentarily closing two contacts controlled by levers associated with the entering and leaving ends, respectively, of the route which it is desired to establish, and in which the levers are free to be operated at any time and the interlocking is eiected electrically by the provision of suitable circuits. One feature of my invention resides in the provision of an improved arrangement of route selecting circuits for a system of this character employing a lesser number of relays and relay contacts than heretofore. Other features of my invention comprise the interlocking of the route selecting circuits by means of indication relays controlled by the track switches and the associated locking relays in such a manner as to prevent any route from being set up which conflicts with another route which is occupied by a train, and in the provision of improved section locking circuits which function in such manner that all of the switches of a route become locked when a train enters a route from either end irrespective of whether a signa] has been cleared to permit such movement or not. Still other objects, purposes and features of my invention will be pointed out as the description proceeds.

My invention is an improvement upon those disclosed in the copending applications for Letters Patent of the United States, Serial No. 14,868 for Interlocking control apparatus, filed April 5, 1935, by Earl M. Allen and Howard A. Thompson now` Patent No. 2,237,804, issued April 8, 1941; Serial No. 118,609, for Railway trafiic controlling apparatus, led December 31, 1936, by Johnl M.

Pelikan, now Patent No. 2,244,401, issued June r 1941; and Serial No. 252,803, filed January 25, 1939, by Lloyd V. Lewis, for Railway traic controlling apparatus.

I shall describe one form of apparatus embodying my invention and several modifications thereof, and shall then point out the novel features of my invention in claims.

Referring to the accompanying drawings, Figs. 1A to 1H, inclusive, taken together illustrate the Cil circuits for a route interlocking system embody- ,55

ing my invention. More particularly, Fig. 1A shows the circuits for the route selecting relays controlled directly by the levers of the operators control panel; Fig, 1B shows a route circuit network controlled by the relays of Fig.V 1.`for controlling route relays for governing `the track switches; Fig. 1C shows a signal control circuit network for controlling relays for governing the signals; Fig. 1D shows section locking relays for electrically locking the switches of a route; Fig. 1E shows the track plan and the switch contro] and locking circuits; Fig. 1F shows the signal circuits; Fig. 1G shows the operators control panel, and Fig. 1I-I. shows the circuits for the indication lamps of the panel. Figs. 2, 3 andI 4 illustrate various alternative forms of switch control circuits which may be used in thesystem of my invention in place of the switch control circuits of Fig. 1E; Fig. 5A shows an alternative arrangement for the section locking relays which may be used inplace of the relays of Fig. 1D; Fig. 5B shows a group of direction selecting relays employed when the section locking relays of Fig. 5A are used, while Fig. 6 shows an alternative arrangement of circuit network for the route relays which may be used in place of Fig. 1B.

Similar reference characters refer to similar parts in each of the several views.-

In order to simplify the description, I shall rst explain the function of the several partsV of the system of my invention illustrated in Figs.

`1A to 1H, inclusive, and shall then describe its operation in detail after which I shall explain the operation` of the apparatus of Figs. 2, 3 and 4, 5A'and 5B, and Fig. 6.

Referring rst to Fig. 1E, the diagram at the top of the sheet represents a plan of the track layout chosen to illustrate my' invention in which, for simplicity, each pair of track rails representing a stretch of track is represented as a single line. While a specic track layout isdisclosed, it is to be understood that the apparatus of my invention is adapted to control any track layout encountered in practice including layouts that vary 14, 1933, for Lamp receptacles.

ments over the various traino routes through the track layout are governed by the signals 2, 4, 6, 8, I and I2, which signals are normally at stop, as shown. Signals 4 and IU are two arm signals each having a main arm such as 4A for governing high speed train movements over the main track in the normal direction and also having a slow speed arm such as 4C which governs train movements over diverging routes and also serves as a call-on signal which may be cleared to admit a train to an occupied block. The remaining signals are all slow speed signals.

As indicated conventionally on the track plan, the rails are divided into track sections by insulated joints, the upper track including the detector sections IT and 5T, an approach section IDT and an advance section 2T, while the lower track includes the detector sections AIT, 3T and 1T, an approach section 4T and an advance section I2T. Each track section is provided with the`usual track circuit having a source of current connected across the track rails at one end as indicated conventionally by the reference character B, and a track relay TR connected across the rails at the other end.

The operators control panel, shown in Fig. 1G, includes a track diagram which is a miniature representation of the track layout to be controlled. In order to enable large track layouts to be more conveniently controlled from a single operators position, it is advantageous to provide as compact an arrangement as possible and to this end the linear light units as used heretofore, as in the disclosure of the above-mentioned Pelikan patent, for example, have been replaced by lamp units K of smaller dimensions, the present arrangement being an improvement upon that disclosed in my Patent No. 2,179,462, issued N0- vember 7, 1939. These units, for example, may

be of the telephone lamp type such as is shown in the Lewis Patent No. 1,897,668, issued Febru- The indicators K include a signal indicator GK having red and green lamps for each route entrance, a white exit lamp XK bearing an arrow designation for each route exit, and a red lamp TK for each detector or approach section which is lighted when lthen remain lighted as long as the track switches of the route remain locked even though the route set up is cancelled manually by the operator or automatically by a train entering the route. To conserve space, the entrance-exit route levers for the ends of the routes, which heretofore in systems of this character have been located on the diagram, have been mounted in a row below the track diagram, as shown, each lever being identified on the panel by the number of the signal at the corresponding route entrance, and on the circuit plans by the reference character F with an identifying numerical prex. The row of levers also includes a group of switch levers numbered I, 3, 5 and 1 for controlling the corresponding track switches individually and independently of the route control, each switch lever being provided with an indicator LK located directly above the lever. Each of the control levers P is of the three-position type and may be moved it normally occupies, suitable levers being shown, for example, in the Lewis Patent No. 1,887,273, issued November 8, 1932, for Circuit Controllers. The route levers preferably are biased by centering springs in a well-known manner so as to return automatically to their center positions when released.

In the circuit plans shown herein, each relay is identified by a letter or combination of letters prefixed by the designation of the switch or signal with which it is associated, and in order to enable the circuits to be more readily understood, they are arranged in the written circuit form with similar circuits grouped together in the same view, and each contact is identified by a number and by showing the designation of the relay which operates it above the contact. Furthermore, instead of showing the local source of current for energizing the relays, I have shown only the terminals which are designated by the reference characters B and C referring to the positive or supply terminal and to the negative or common return terminal, respectively, of the local source of current. For example, in Fig. 1E, each detector or switch section track relay TR is provided with a slow pick-up slow release track repeater relay TP, the circuit for relay ITP, for example, being normally closed from one terminal B of the local source over contact I3 of relay I'I'R through the winding of relay ITP to the other terminal C of the source.

Each track switch of the layout is actuated by a power operated switch machine SM, as illustrated for the crossover switches iA and IB. The switch machines may be of the type shown in the Zabel Patents Nos. 1,293,290 and 1,413,820, having a reversible motor controlled by a polarized switch control relay WR, as indicated diagrammatically by dotted line connections in the drawing. It is to be understood that each switch or pair of switches will be operated to normal, as shown, or to reverse, when the corresponding control relay WR is energized and its polar contacts are closed to the left or right, respectively.

Each switch machine is provided with the usual indication circuit controller as disclosed in the Zabel patents hereiribefore referred to, governing circuits for controlling a, polarized switch indication relay such as the relay IWP which is energized with its polar contacts closed to the left or right only when the corresponding switches Y are locked normal or reverse, respectively.

Ato the left or right from the center position which Each switch indication relay WP in Fig. 1E controls a pair of switch correspondence relays such as the relays INC and IRC, each of which is energized only When the corresponding polarized relay W'P is energized in a position corresponding to that of the associated switch control relay WR, as will be readily apparent from the drawings.

The correspondence relays NC and RC control the signal network circuits of Fig. 1F, and control the selection of the section locking relays of Fig. 1D in such a manner as to provide a series of relays for each direction for each route which becomes deenergized to lock the switches 0i a route when the route becomes established for a trafc movement in the corresponding direction.

The signals may be of any desired type, but as herein illustrated, it is to be understood that they are of the Well-known searchlight type having a mechanism G of the form disclosed in the E. J. Blake Reissue Patent No. 14,940, of August 3l, 1920, which mechanisms are controlled over a signal network of interconnected circuits in the manner shown in Fig. 1F. Each signal is provided with the usual back lock or signal indication relay RGP, as shown, which relay is energized only when the lcorresponding signal indicates stop. Each relay RGP controls an approach locking stick relay AS of corresponding number such as the relay 4AS of Fig. 1F and also controls the lamps of the associated signal indicator GK of Fig. 1H.

Each slow speed signal is arranged to indicate either clear or stop. A distant relay 4DR or IIJDR, Fig. 1F, controlled by .the next signal in advance, not shown, controls the polarity of the current supplied to the mechanism G for each high speed signal 4A or IGA, to provide a third or caution indication. The circuits for relays DR are omitted since they form no part of the present invention and suitable circuits are wellknown.

The circuits are so arranged that the signal at the entrance to a route will clear automatically as soon as all switches for the route are locked in the required positions. This is accomplished through the medium of the signal control relays R shown in Fig. 1C. In case the high speed signal 4A or IBA fails to clear when the corresponding route has been set up, the call-on signal 4C or IilC may then be cleared manually by re-cperating the lever for the entrance end of the route to pick up a call-on stick relay` such as the relay ICOS or HlCOS shown in Fig. 1A.

Each signal control relay R also controls the approach locking relay AS for the associated signal in the manner indicated diagrammatically in Fig. 1F. To simplify the drawings, the circuits for the approach locking stick relays AS are not shown in detail further than to indicate by dotted line connections that each relay AS is energized only when both the signal control relay R. and the mechanism G for the corresponding signal are deenergized. The circuits for the approach locking relays may be arranged as disclosed in the Allen and Thompson application, or in my patent, hereinbefore referred to, to

provide the usual time and approach locking of the switches and of opposing signals so that when a signal assumes the stop position, the energization of the associated relay AS is delayed for a predetermined time interval provided the signal is put to stop manually, this delay being nullified by the release of the corresponding track relay when the signal is automatically put to stop by a passing train. The approach locking relays AS control the section locking relays ES and WS by means of the circuits of Fig. 1D, J

which relays provide directional control of the switch locking and function in a well-known manner so that when a train enters a route, the locking of each switch ahead of `the train will be maintained while the locking of each switch in the rear of the train will be released as soon as the corresponding track section is vacated. This is accomplished by arranging the circuits so that when a signal is cleared, a series of relays ES or WS selected by the switch correif:

a manner that when a signal control relay R becomes energized to clear the signal for a route, the` pick-up circuit for the control relay WR for each swtchof the route is opened, but each relay WR is held energized b-y the relay NCor RC for the switch it controls to electrically lock the switch in the position it then occupies until the corresponding section of the route is vacated. The switch locking relays LS also control the circuits of the signal mechanisms G of Fig. 1F in such a manner that the clearing of' a signal in response to the operation of its control relay R is made dependent upon the locking of each switch of the corresponding route, while the relays AS also control the signal circuits of Fig. 1F and the route selecting circuits of Fig. lA'to provide time and approach locking for opposing signals.

In order to simplify the construction, the relays employed in the system herein disclosed are arranged in two groups. One group comprises all of those relays so far described which relays have to do with the safety of train operation, and it is to be understood that these relays are of the standard type generally employed in the railway signaling art. The second group of relays includes those which are used only for communication purposes such as the relays of Figs. 1A and 1B which govern the selection of routes in response to route lever operation. and such indication repeating relays as are required for the control of the route circuits and of the indication lamps associated with the operators control panel. These relays are preferably small quick acting relays of a type such as that shown in the Lewis Patent No. 1,815,947, granted July 28, 1931, for Electrical Relays, and are preferably mounted in a compact array in the control cabinet at the rear of the operators panel.

The indication repeating relays referred to include a switch indication relay for each position of each switch or crossover, such as the relays INWK and IRWK of Fig. 1E which relays, as will be clear from the drawing, are normally deenergized repeaters of the correspondence relays INC and IRC, respectively, and also include the indication relays SP of Fig. 1H, there being one relay SP for each'track section of the layout. The relay SP for each section is controlled by the section locking relays ES and WS as shown in Fig. 1H.

The selection of a desired route bythe operation of the apparatus of my invention is effected in two stages, the first of which is initiated by momentarily rotating the button P identifying the entrance end of the desired route, in a direction corresponding with the desired direction of traffic movement, and is completed by the resulting energization of a selecting circuit, or a series of tandem-connected selector circuits, for each available route having the same entrance as the desired route, whereupon an exit indicator for each of these routes becomes lighted on the track diagram to inform the operator which exits are available;

These route selecting circuits are shown in Fig. 1A, the circuits for each direction being combined in circuit networks similarin form to the track layout, with movable contacts at the points corresponding to the locations of the track switches whichare operated upon the energization of any selecting-circuit to isolate that circuit from those for routes havingdilferent entrance ends.

The route selecting apparatus controlled directly by the route levers P as ShQWIl. Fig 1A includes a. route selecting or entrance stick relay PS for each route entrance and an exit relay XS for each route exit. The exit relays for the two directions are controlled over the separate networks referred to, by the entrance relays PS, and

govern the route relays of Fig. 1B. The circuits vof Fig. 1A include certain additional route selecting relays identified by the suix E when associated with circuits for traffic movements from left to right, and by the reference W when associated with trai-Tic movements from right to left. One such selecting relayis required for each switch which forms the junction of converging routes provided the switch is located in a section which is not adjacent the entrance end of a route,

'examples being the relays lBNE, IRW and EBNW relays, such as the relays 8E and 8W.

The second stage of the route selection is initiated by the momentary rotation, in a direction Vcorresponding with the desired direction of traffic movement, of the button P for the exit end of a route, to energize the exit relay XS for the n desired route, which relay in turn completes a route circuit in Fig. 1B or Fig. 6 to energize a route relay NR or RR for each switch of the desired route.

These route circuits, like the route selecting circuits of Fig. 1A, are combined in a circuit network corresponding with the track layout, but differ in that they are non-directional, that is, the route relays NR and RR are connected to vthe route circuits in parallel, and eachv route circuit is arranged to be energized in response to the operation of the exit relay XS at either end. The energization of the route relays for a route opens contacts in the circuits of Fig. 1A and Fig. 1B or 6 which fully isolates the circuits for the selected route from the corresponding circuits for conflicting routes.

This completes the selection of the desired route, which then becomes established automati- 'cally due to the operation of the switch control relays WR of Fig. 1E, hereinbefore referred to, by the route relays NR and RR. When the track 'switches assume the required positions the proper signal control relay R, Fig. 1C, becomes energized to lock the switches in the required position, to clear the signal at the entrance to the selected route, and to indicate the route by lighting a corresponding series of lamps on the track diagram. i

The established route may be cancelled manually by operating the entrance relay momentarily in a direction opposite to that correspond- Ving to the established trafc direction, otherwise it will be cancelled automatically when a train enters the rst track section. In either case, the route selecting circuits of Fig. 1A for each section of the route are maintained isolated until the switch locking for such section becomes released, this being accomplished in a novel manner through the medium of the switch indication -relays NWK and RWK.

Ishall now describe the operation of the apparatus of Figs. 1A to 1H, inclusive, under diiferent assumed conditions, tracing the circuits in detail. I shall'iirst assume that the apparatus is in the normal condition as shown in the drawings and that the operator desires to clear signal 4A to pass an approaching train over route 4-I2. When the train enters the approach section 4T, Fig. 1E, the release of track relay 4TR closes back contact I4, Fig. 1H, to complete the circuit for the red lamp of the approach indicator 4TK, this indicator becoming lighted to inform the operator of the approach of the train.

Normally, all the indication lamps are dark and each route lever P is free to be operated to the left or to the right to mark the entrance or exit to a route.

To set up route 4-I2, the operator will first move lever 4P momentarily to the right to pick up relay 4PS. The pick-up circuit for relay 4PS may be traced in Fig. 1A from terminal B, front contact I5 of track relay AITR, right-hand contact I6 of lever 4P, back contact Il of route relay INR, relay 4PS, back contact I8 of the associated exit relay 4XS to terminal C. Relay 4PS upon becoming energized completes at its front contact I9 a stick circuit which extends to terminal B at contact I5 of relay AITR over the normally closed contact 20 of lever 4P, and in Fig. 1H, relay 4PS completes an indication circuit from terminal B, back contact 2l of relay 4COS, front contacts 22 and 23 of relays 4RGP and 4PS through the red lamp of indicator 4GK to terminal C, thereby indicating that point 4 on the track diagram is an entrance point. Relay 4PS by closing its front contact 24, Fig. lA, completes circuits for relays 8E and 'IBNE and for the lampsfor the exit indicators BXK, IIlXK and I2XK, thereby indicating each available exit on the track diagram, and also prepares circuits for relays 8XS, IDXS and I2XS.

The circuit for relay 8E corresponds to route -4-8 and extends from terminal B, contact 24 of relay 4PS, back contacts 25, 26, 2l and 28 of relays INR, INWK, 2PS and 8XS, relay 8E, front contacts 29 and 30 of the approach locking relays IZAS and IDAS for the opposing signals I2 and Ill to terminal C. Relay 8E by closing contact 3| causes lamp SXK to be lighted and at contact 32, relay 8E connects relay 8XS in place of relay BPS to contact 33 of lever 8P.

Lever 8P is now conditioned to function as an exit lever and if moved to the right momentarily, relay 8XS is picked up to be held subsequently over its stick circuit including its own front contact 28a-nd contact 24 of relay 4PS. As long as lever 8P is held reversed, relay 8E is held energized over its stick circuit including contacts 34 and 35, but when lever 8P is restored to normal, relay 8E releases to reestablishlever 8P as an entrance lever and lamp BXK remains lighted, being energized over contact 36 of relay 8XS after relay 8E releases. However, in the present instance, it is to be understood that lever 8P is not operated.

The circuit for lamp IIlXK corresponds to route 4-I0 via 5 reversed and extends from terminal B, contact 24 of relay 4PS, back contacts 3l to 46, inclusive, of various relays as designated on the drawing, lamp IBXK, front contact 41 of relay IUAS to terminal C.

Lever IDP is therefore conditioned to function as an exit lever and if moved to the right momentarily, completes at contact 48 a branch of the circuit for lamp IOXK comprising a pick-up circuit for relay IUXS, and relay IUXS upon becoming energized completes its stick circuit atcontact 49. However, in the present instance, it is to be understood that lever IUP is not to be operated.

The circuit for relay 1BNE corresponds to the main line route 4--I2, and extends from terminal B, contact 24 of relay 4PS, back contacts 31 to 4I, inclusive, and thence over back contacts U to 53, inclusive, of the relays designated on the drawings through relay 1BNE to terminal C. Relay 'IBNE picks up and completes a circuit from terminal B at its front contact 54 through lamp- IEXK, contact 55 of relay IZAS to terminal C, thereby lighting the exit lamp I2XK and conditioning lever I2P to function as an exit lever. The operator therefore has a choice of three exit points and it will be assumed that he now completes the selection of the desired route #1I- I2 by moving lever I2P momentarily to the right, completing the pick-up circuit for relay IZXS Vat contact 56. Relay I2XS picks up and completes its stick circuit at contact 51 and is held energized in multiple with lamp IZXK over Contact 24 of relay 4PS.

Relay IZXS upon picking up, completes in Fig. 1B a branched route circuit for energizing va route relay for each switch of the selected route. The selected route circuit extends from'terminal B over contact 58 of relay IZXS, front contact 59 of relay 1BNE, and from this point one branch extends through rectier 69, relay 1NR toterminal C and another through rectifier 6I, relay 5NR to terminal C so that relays 1NR and 5NR are energized. When relay 5NR picks up, the route circuit is extended from contact 59 over front contact 62 of relay 5NR, and back contacts 63, 66 and 65 of relays SBNW, SPS and 3RR, and from back contact 65 one branch extends through relay SNR to terminal C and another branch through rectifier 66 and relay INR to terminal C so that relays SNR and INR are also energized.

When relay INR picks up, it completes, in Fig. 1H, a circuit from terminal B, contact 61 of a flasher or interruptor relay CT, back contact 68 of relay INWK, front contact 69 of relay INR, front Contact 19 of relay ILS through the red lamp of indicator ILK to terminal C causing the indicator lLK above lever IP on the control panel to display a flashing indication. It is to be understood that each of the remaining indicau tors LK is provided with circuits, not shown, which are similar t0 those for indicator ILK, and it follows that in the present case each displays a flashing indication, because each of the route relays NR is energized.

Referring now to Fig. 1A, it will be seen that the route relays controlled by relay IZXS open the selecting circuits for each of the diverging routes having the common entrance point 4 except that for the selected route lI-IZ. Thus relay ENR opens its back contact 42 in the selecting circuit for route Il-IU via 5 reversed, thereby extinguishing lamp IDXK, and relay INR opens its back contact in the selecting circuit for route d-B, thereby releasing relay 8E and extinguishing lamp BXK. The route relays also prevent closing the selecting circuits for any of the converging routes having the exit point I2 except the selected route 4-I2. Thus relay 3NR opens the circuit for relay 6PS which controls the selecting circuits for the conflicting route 6-I2 and for the cross route S-Ill, at its back contact 1I. The selecting circuit for route 8-I2, which extends from terminal B at front contact 12 of relay SPS to relay I2XS, is now open at back contact 13 of relay 1NR as well as at back contact 54 of relay 1BNE. c In the selectingfcircuit network for the opposite direction, the circuit for the opposing route I2-4 which extends from contact 18 of relay I2PS to relay IXS is iso-V lated from the others by the openvback contacts 14, 15, 16 and 11 of relays INR, SNR, ENR and 1NR and is held open atfront contact 18 of relay IZPS, this relay being held deenergized because its circuit includes b-ack'conta'ct 19 of relay IZXS which contact is now open. Similarly, in Fig. 1B, it will be readily Aseen that the circuits for the route relays IRR, SRR, 'SRR and 1RR are each held open at one or more points. and route relays for route 4-I2 Aare therefore electrically isolated from the relays for al1 conflicting routes.

Referring now to Fig. 1E, it will be seen that relay INR upon becoming energized completes the normal operating circuit'vfor the switch control relay IWR which extends from terminal B, resistor 80, front contacts 8I and 82 of relays INR and ILS, relay IWR, contacts 83 and .84 of relays ILS and INR to terminal C. vRelay IWR picks up in its normal direction, but since route 4-I2 requires all track switches to occupy their normal positions, no switch :operations are required in the present case and eachof the polarized indication relays such as relay IWP as well as each of the switch control relays WR already occupies its normal position, as shown, and consequently each of the normal correspondencev relays NC is energized over a circuit similar to that for relay INC which circuit extends from terminal B, front contact 88 and normal polar contact 81 of relay IWP, relay INC, normalpolar contact 86 of relay IWR to terminal C., It fol-k lows that when relay IWR picks up, relay kINWK becomes energized over the circuit fromterminal B over front contact'85 `of relay IWR, back Vcontact 89a of relay IRC and front contact 8920i relay INC through relay INWK to terminal C. Each of the remaining relays WR functions similarly and therefore the `normal indication repeating relay .NWK for each` switch of 'route 4-I2 becomes energized, and closes a front contact such as contact 68 of relay INWK, Fig. 1H, to .connect .the lamp of the corresponding indicator ILK directly to terminal B, so that each of the indicators LK Anow becomes steadily lighted.

Referring now to Fig. 1C, `when the .relays NWK for all the track switches of route --IZ become energized, .indicating that the routegis fully established, Va circuit is completed for :the signal control relay 4R from .terminal B, front contact 90 of relay `I2XS, contacts 9| to 94 of the relays NWK, back contact 95 of relay XS, relay 4R to terminal C. Relay dR therefore picks up with the result that its back contact 96, Fig. 1F, in the circuit for relay AAS is opened. Relay lIAS consequently releases and opens .its Contact 91, Fig. 1D, to release the section locking relay AIES. Relay AIES in vturn opens contact 98 to release relay SES, land relay SES upon releasing opens contact 99 in the circuit for relay TES. Relay 1ES upon releasing closes back contact H10 to complete the stick circuit for relay 1WS to prevent the release of relay 1WSv when section 1T becomes occupied subsequently by the train moving from left to right over route -4'-I2,

contact |00 being for a purpose described-here-- inafter in connection with Figs. 5A and 5B. Re

lay IAS by closing 'back contact IUI, Fig. r1F, prepares a circuit .over front .contacts |02 `and The selectorv |03 of relay 4R for the signal mechanism 4AG.

Referring now to Fig. 1H, it will be seen that relayAIES upon releasing completes at contact |04 a circuit for relay AISP. Contact |04 also connects terminal B to the circuit for relay ISP, but that relay does not pick up because back contact |05 of relay INWK is now open. Relays 3ES and 'IES upon releasing complete the cir cuits for relays 3SP and 'ISP at their back contacts |06 and |50, Fig. 1H.` Relay AISP picks up and at contact |01 completes circuits for indicators AIK and AINK, the circuit for the latter including the closed contact |08 of relay INWK. Relay 3SP picks up and at contact |09 completes circuits for indicators 3NK and 5NK over contacts IIO and III of relays 3NWK and 5NWK, respectively. Relay 'ISP picks up and at contact H2 completes circuits for indicators 1NK and 1K, the circuit for indicator 'INK also including contact I|3 of relay'lNWK, so that now all the white lamps of the row representing route 4--l2 on the track diagram are lighted.

At the same time, relay AIES` opens its front contact II4, Fig. 1E, thereby releasing the switch locking relay ILS which at its back Contact 10, Fig. 1H, completes a circuit for maintaining lamp` ILK lighted `after the route relay INR is released. Similarly, relay SES opens its front contacts |I5 and IIB, Fig. 1E, to release the switch locking relays 3LS and 5LS and relay 'IES opens contact ||1 to release relay 1LS. A11 of the track switches are now locked electrically, the operating circuit by which the relays WR are controlled by the route relays NR and RR being open at the front contacts of the relays LS. However, the switch control relays WR are held .energized over holding circuits as long as the switches are locked, as illustrated for relay IWR in Fig. 1E. The closing of back contacts 82 and 83 of relay ILS, it will be seen, completes a holding circuit for relay IWR extending over front contacts I|8 and ||9 of relay INC to hold relay IWR in its normal position as long as relay ILS remains released. The kclosing of other back contacts of the LS relays, namely, the contacts |22, |23, |25 and |21, Figs. 1F, completes the circuit for the signal mechanism 4AG which circuitl extends from terminal B, front contacts |20 and I2I of relays |2AS and TNC, back contacts |22 and I23'of relays 'ILS and 5LS, front contact |24 of relay 5NC, back contact |25 of relay 31S, front contact |26 of relay 3NC, back contact |21 of relay ILS, front contact |28 of relay INC, back contact of relay 4AS, front contact |02 of relay 4R, back contact |29 of relay 4C OS, normal polar contacts |30 and I3| of relays` WP and IWF, front contacts |32, |33, |34 and I 35 of relays I2TR, '|TR, 3TR and AITR thence over the pole changer contacts |36 and |31 of the line relay 4DR through the winding of mechanism 4AG to terminal C at contact-,|03 of relay Signal 4A now clears and relay 4RGP releases in response to the opening of back contact |38 of mechanism 4AG and at its contact 22, Fig. 1H, relay 4RGP controls the circuits for indicator 4GK to cause the indication displayed thereby to change from red to green.

I shall next assume that the approaching train accepts the cleared signal 4A and enters the first detector section AIT of the route. The track relay AI'IR and its slow-acting repeater relay AITPrelease successively, relay AITP by closing its back contact |39, Fig. 1H lighting the red lamp indicator AITK to indicate that section AIT is occupied. Relay AITR, by opening contact I5, Fig. 1A, releases relay 4PS, and relay 4PS, by opening contact 24, releases relay lBNE Which relay, in turn, releases relay |2XS, causing indicator |2XK to become dark. Referring now to Fig. 1B it will be seen that the route relay circuits are arranged in a novel manner so that the selected circuit is not interferred with by the release of the entrance relay and of the selector relay 1BNE controlled thereby but remain intact as long as terminal B remains connected to the circuit at the front contact of the exit relay, due to the provision of a connection which is completed over front contact |40 of relay 'INR after relay 1BNE releases and drops its contact 59, and that the route circuit is not opened to release relays INR, SNR, 5NR and 1NR until relay IZXR releases to open contact 58. Heretofore in circuits of this character, it has been necessary either to use front contacts'only of the selecting relays, requiring a larger nurnber of such relays, or to employ separate net- Work circuits for the two directions for the route relays.

When the route relays are released, relay 4R, Fig. 1C, is released by the opening of contact 90 of relay I2XS, and from Fig. 1A it will be seen that the selecting circuit for route 4-I2 remains isolated and the circuit for selecting any route conflicting with route 4--I2 governing trafc movements from left to right cannot be set up at this time because these conflicting circuits include open back contacts such as contacts 26, I4 I, 43 and |42 of the energized relays NWK in series with the NR relay contacts 25, 1|, 42 and 13 hereinbefore referred to. Similarly, the circuits for selecting conflicting routes for governing traic movements from right to left cannot be set up because they include the open contacts |43 to |46, inclusive, of the NWK relays, which relays are held picked up by the WR relays as Along as the switch locking remains effective. This arrangement is an improvement upon the arrangement disclosed in my Patent No. 2,179,462, where the sectional release of the route selecting circuits is provided by including front contacts of the switch indication relays in the circuits and by bridging these contacts by front contacts of the switch locking relays. The present arrangement possesses the advantage not only of requiring fewer contacts, but of simplifying the wiring, since the locking relays are of a .different type and are usually located at some distance from the selecting and route relays.

When relay AITR releases, its contact |35 opens, deenergizing mechanism 4AG which releases to put signal 4A to stop, and then relay 4RGP picks up and by opening its back contact 22, Fig. 1H, restores the entrance indicator 4GK to its normal dark condition. Relay 4RGP also completes a circuit for relay 4AS at contact |41, Fig. 1F. Relay 4AS now picks up in the usual manner and at contact 91, Fig. 1D, prepares a circuit for relay AIES, which relay, however, remains deenergized as long as section AIT is occupied and consequently the series of lamps representing route 4-I2 on the diagram remain lighted. It is to be understood that each of the track indication lamps such as 3TK and 'ITK is controlled by the associated track repeater relay as illustrated for lamp AITK in Fig. 1H, and that lamps STK and 1TK become lighted successively as the train passes over route 4|2.

When'section AIT is vacated, relay AI'IR picks up and at contact |48, Fig. 1D, completes locking of switch IB is in this manner releasedV of switch 3'is released as indicated by the track diagram, permitting a conflicting route such as 4-I0, G-I or 5|2 to be set up if desired. When section 'IT is vacated, relay 'ITR closes its front contact in the circuit for relay 'IES and relay 'IES picks up, opening contact |50, Fig. lI-I, to release relay TSP, and closing contact II l, Fig. 1E, to pick up relay ILS. Indicators INK, ITK and 'IK now become dark, thereby completing the restoration of the apparatus to its normal condition.

I shall next assume that with the apparatus in normal condition as shown that levers 3P and IZP are operated momentarily to the left, in the reverse order, button IEP being operated rst to set up route |2-4 for a train movement from right to left. In response to the operation of lever IZP to the left, relay |2PS picks up and is held energized over its stick circuit and at contact 7B, Fig. 1A, completes circuits for relays 8W and EBNW, as will be apparent from the drawing. Relay SW picks up and at contact |I completes a circuit for indicator ZXK. A branch of this circuit extends over contacts |03 and 74 through relay IRW, but this branch is open at contact |53 of relay MBPS, Relay 5BNW picks up and at contact 54 completes circuits for indicators :SXK and SKK. Relay |2PS also completes a .circuit not shown, but similar to that for indicator 2PK, Fig. lI-I, for lighting the red lamp for indicator IZGK. Since route |2-f.'` is to be selected, the operator now moves lever IiP momentarily to the left to Ypick up relay XS which is then held energized over its stick circuit including its own front contact |55 by relay 5BNW, which relay in turn is held energized by relay I ZPS.

Relay iXS upon picking up closes contact |55. Fig. 1B, to pick up relays INR and 3NR, and a branch of the circuit for these relays is completed over front contact 63 of relay 5BNW to pick up relays SNR and 1NR. When these relays Dick up, indicator ESXK, Fig. 1A, is extinguished by the opening of back contact I5 of relay BNR and relay 8W released and indicator ZXK extinguished by the opening of back contact l1 of relay 1NR. The remaining operations are similar to those already described, and it will be readily apparent from the drawings that relay IZR, Fig. 1C, will pick up over front contact 05 of relay XS as soon as each of the relays NWK pick up, and that relay IZR will release relay |2AS, Fig. 1F. It will also be apparent, from Figs. 1D and 1E that relay I2AS1 upon releasing will cause the successive release of the section locking relays of the series comprising relays 1WS, 3WS and AIWS to release the switch locking relays ILS, 5LS, 3LS and ILS to permit the clearing of signal I2 in a manner similar to that already described in connection with signal 4.

I shall next assume that the operator cancels f route |2-4 manually, by moving lever IZP to the right to release relay IZPS and all of the relays controlled thereby. Signal I2 Will assume the stop position and relay |2RGP will pickup, but it is to be understood that relay I 2AS will remain deenergized for a predetermined time interval to provide the usual time locking to prevent the reversal of traiiic direction directly in advance of the train approaching signal I2. Under this condition, not only is front contact |20 of relay IZAS, Fig. 1F, held open to prevent the clearing of signal 4A or 4C' for route 0-I2, but contact 55 of relay I2AS, Fig. 1A, also remains open to prevent the lighting of lamp IZXS or the energization of relay IZXS to set up route 4-I2, until the time interval has expired.

Returning now to a consideration of route 4-I2, I shall assume that a train governed by signal 4A has entered the route, and that the operator desires to clear the `call-on signal 4C to admita second train to section AIT while that section is still occupied by the first train moving from left to right. A connection to terminal B for picking up relay 4PS becomes available at back contact I5a of relay AITP shortly after relay AI'IR is released by the first train entering section AIT and it follows that the cancelled route 4-I2 may then be set up again by moving levers 4P and |2P momentarily to the right as previously described. Relay 4R will pick up, but mechanism 4AG, Fig. 1F, Will remain deenergized because its Circuit is open at contact |35 of relay AITR, or at contact |34, |33 or I 32 if the train has advanced beyond section AIT, and indicator IGK will continue to display a red light after the route has been fully set up.

To clear signal 4C for route 4-|2,the operator will again move lever 4P momentarily to the right `after he vhas picked up relay 4R as above described, the operation of lever 4P in this case completing a pick-up circuit for relay 4COS, Fig. 1A, from terminal B, Contact |5a of relay AITP or contact I5 of relay AI TR, contact I6 of lever 4P, front contact I1 of relay INR, front contact |51 of relay IRGP, relay IICOS, Contact |58 of relay 4R to terminal C, and relay 4COS will pick up to complete a stick circuit over contact |58, which circuit extends to terminal B over its own -contact |59.

Relay llCOS completes a circuit in Fig. 1F for mechanism ACG which is a branch of the circuit for mechanism IAG already traced, extending from terminal B at contact |20 of relay IZAS as already described to contact |02 of relay 4R, and thence over front contact |29 of relay 4COS, the Winding of mechanism IICG, contact |03 of relay 4R to terminal C.

Signal 4C now clears, relay IRGP releasing vdue to the opening of the back contact |60 of mechanism 40G.

When relay dCOS picked up, it caused indicator AACG to display a distinctive iiashing red vindication by closing its front Contact 2|, Fig. 1H, which is connected to terminal B 'over .Contact 51 of the continuously operating flasher relay CT. When signal 4C clears, indicator 4GK will display a continuous flashing green indication due to the closing of back contact 22 of relay ARGP. Since relay 4PS is now energized over back contact ISa of relay AI'IP, it will not release if the second train enters section AIT before the iirst train Vacates that section. In this case, the operator may cancel the route manually by operating lever'4P momentarily to the left to open the stick circuit for relay 4PS at contact 26.

I shall next assume that with the apparatus in the normal condition, as shown, that the operator moves levers 4P and 8P momentarily to the right in that order to establish route 4-8. The operation of lever 4P energizes relay 4PS which causes relay 8E, Fig. 1A, to pick up, as has already been described. It will be seen that the circuit for relay 8E includes contacts` of the approach tablishing its stick circuit at front contact 28,

and relay 8E releases due to the opening of contact when lever 8P is restored to normal. Lamp 8XK is now energized over contact 36 or relay 8XS and at contact |6|, Fig. 1B, relay BXS closes the circuit for relay IRR which picks up to complete the route selection.

Relay IRR at contact 31, Fig. 1A, opens the circuits forv lamps IOXK and IZXK and also opens contact |62 in the circuit for relay 2PS. Relay IRR closes contacts |63 and |64, Fig. 1E, cornpleting the reverse energizing circuit for relay IWR which relay reverses and operates the track switchesl IA and IB to reverse, this operation being indicated by the flashing of lamp ILK, the circuit for which is closed from terminal B over contact 61 of the flasher relay CT, Fig. 1H, back contact |65 of relay IRWK, front contacts |66 and 1I) of relays IRR and ILS, lamp ILK to terminal C, lamp |LK becoming steadily lighted when the switches complete their movement to reverse to energize relays IWP, IRC and- IRWK. v

When relay IRWK picks up, the closing of its contact |61, Fig. 1C, completes a circuit for relay 4R extending to terminal B at contact |68 of relay 8XS and relay 4R picks up, releasing relays 4AS, AIES and ILS and thereby completing a. circuit in Fig. 1F for the signal mechanism 4C.

Referring to Fig. 1H, it will be apparent that relay AIES now completes the circuits for relay ISP as well as that for relay AISP and that the route indicator lamps AIK, IRK and IK are lighted to indicate route 4-8 on the diagram.

I shall next assume that the operator sets up route 8| Il by moving levers 8P and IUP momentarily to the right. It will be seen that lever 6P serves as an entrance lever as longvas relay 8E is deenergized, that is, not only when no lever in the rear such as 2P or 4P has been operated, but also following the release of relay 8E after relay 8XS has been energized. Since relay 8E is now deenergized, the closing of contact 33 of lever 8P completes the pick-up circuit for relay 8PS which relay picks up closing iront contacts 44 and 12 to energize the exit indicators |9XK and |2XK. The subsequent closing ofthe right-hand contact 48 of lever IGP causes relay |0XS to become energized.

Referring now to Fig. 1B, it will be seen that a circuit is now closed from terminal B, contact |69 of relay IUXS, rectifier 69a of relay 1NR to terminal C. Relay 1NR therefore picks up and completes a branch circuit from terminal B at contact |69 over front contact |10 of relay 1NR, back contact |1| of relay IUPS, front contact |12 of relay SPS, rectifier Bla, relay 5NR to terminal C. Relay SNR picks up and at its back contact |14 disconnects the branch circuit which extends over back contact |12 of relay BPS through relay SRR to terminal C. The circuits are arranged so that relay SRR does not become energized upon the closing of back contact |12 following the release of relay SPS, but relay 5NR is held energized over its front contact |14 until terminal B is disconnected from the branched route circuits by the opening of contact |69 of relay I DXS. The remaining operations involved in completing the set-up for route 8|0 and the clearing of signal 8 are similar to those already described and a detailed description is believed to be unneCeSSaly.

I shall next assume that the apparatus is in the normal condition as shown and that levers |0P and 4P are moved momentarily to the left in that order. There are two routes |0-4, a preferred route over crossover reversed and a secondary route over 5 reversed, the arrangement being such that the preferred route is selected automatically if available. The operation of lever IUP to the left completes the circuit for relay IOPS at contact |15, Fig. 1A, and relay IUPS picks up and closes contacts |16 and |11 to energize relay 8W and lamp 4XS. Relay 8W closes contact 5|, thereby energizing relay IRW over the circuit extending to terminal C at front contact |53 of relay IOPS, and relay IRW upon becoming energized, at its back contact |52 opens the circuit for lamp 4XK which extends to terminal B over contact |11 of relay |0PS, but maintains lamp 4XK energized by reason of the connection to terminal B over front contact |52. It will be seen, therefore, that if lever 4P is now moved momentarily to the left to close contact |18, relay 4XS becomes energized over the route circuit for route IIJ-4 via reversed, and that preference is given to one 'alternative route over the other when both are available in a very simple manner, as the choice depends merely upon which of the two converging route circuits includes the selecting relay such as IRW. Relay 4XS when energized completes circuits in Fig. 1B

` from terminal B over front contacts |56 and |19 of relays 4XS and IRW for energizing the route relays IRR, 5NR and 1NR for the preferred route.

The secondary route III-4 over 5 reversed is selected in case relay IRW is prevented from picking up, as would be the case if crossover were locked normal due to the persence of a train in route 2-8, for example. In this case, relay INWK would be energized and the circuit for relay IRW in Fig. 1A would be open at back conta-ct |43 of relay INWK. The energization of relay 4XS with relay IRW deenergized results in the energization of the route relays INR, 3NR, SRR and 1NR for the secondary route III-4, as will be apparent from Fig. 1B.

The apparatus is also arranged so that a secondary route may be selected manually by the operation of one or more of the individual switch levers which define such route. This is accom;

plished'by includingv contactsof the'switch leversv Thus, for exam-v ple, the; secondary route IO-d over reversed" maybe selectedeven though the preferred route inthe route selecting circuits.

be noted that the circuit for relay IRW has aA direct connection toterminal C over its own front contact |82 which iscompleted when' relay IRW picks up. This isY provided in order to prevent the release of. relay IRW due to the inadvertent movement `of lever IP or I'Pafter the circuits for a route requiring.theenergization of' that relay have been set up.

The arrangements for operating the track switches individually will bel readily apparent from a. consideration. of'Fig'. 1E. AIt will be seen-that if' lever IP is movedto the-left or right while relay ILS is energized, a circuit is completed from tere minal B, resistor- 8,0, contact |83of lever P through the winding of relay IWR, contacts 82' and 83 of relay ILS and the left-hand or right-hand contact iii-*Ici 'lever IP toterminal C to operate the contactsof relay IWR to a position to correspond with that of thelever contact. In systems employing individual switch levers,.it is desirable to arrange the levers so they are ineffective unless operated while theV switch locking is released. rl`his is accomplished as in my Patent No. 2,179,462 by providing each switch lever with a center contactwhich musty be closed inorder to effect the energization of the associated locking relay LS.`

Thus relay |LS has alpickeup circuit which eX- tends from terminal. B at contact |35 of relay AIWS over front Contacts of the section locking and track relays for sections IT and AIT through the windingY of' relay ILS, centerjconta'ct Il of lever IP to terminal C, and a stick circuit independent of the lever which extends to terminal C over front contact |86 of relay ILS.

In order to indicate the response ofv theftrack switch to the operation. of the individuall switch' lever, normal and reverse contacts of each lever, such ascontact |37 of lever IP, Fig. 1H, are included in the` circuit for the corresponding indication lamp iLK in multiple with the route relay contacts such as contactsl' and |66; It will be apparent that whenever lever IP'is moved toA left or right, lamp ILK will flash until the switches assume the corresponding position and then will be steadily lighted until the lever is restored toits normal center position.

In the foregoing, I have explained but a few of the many possible operations of the apparatus of Figs. 1A to 1H, inclusive, but it is believed that since the remainingloperations are carried out in a manner generally similar to those described, that they will be readily understood without further explanation;

It will be noted that the switch control circuits of. Fig. 1E are arranged to require but two wires from the tower or control oice to each relay WR lor theY control of the relay. This is of advantage wlien the. relaysWR` are. at' a. considerable distance from a tower, but when this distance is theotherrelays in the tower, the arrangement of Fig. Z'employing fewer control contactsl may be preferred.v In Fig'. 2, the relay IWR has two oppositelyconnected windings and-when the normal route relay INR is picked' up or when lever |P' isY moved to the left, or normal control position, the upper or normal winding of relay IWI-i'.V is

energized from. terminal B, contact |88 ofl relay' ILS, relay IWR, frontcontact 83 of relay ILS,

contactfl'of'relay INR (or'left-hand contact' |84l of` lever IP) to terminal C. When relay ILS releases, anormal holding circuitis established.

fromiterminall B, contactV |89 and the normal win'dingof relay' IWR, back contact 83 and the' cuits of Fig. 1E.'

InA Figs. lE'and 2, the switch 'indication relays NWK and RWKl are normally deenergized'. It`

may` be preferred to display indications of the positions of 'thetrack switches continuously and i to maintain the switch control relays energized ilar to those of. Fig. 2, but thatthe holding circuit,` does notinclude back contacts of, relay IDS and. hence isnot opened when relay |LS'- picks up, and

therefore, relay IWR' is normally energized. As.- sumingrelay IWRlto occupy itsnormal position, asshown, iflcontact |64 of. the reverse route relay IRR'is closed, current will flow from. terminal B at contact |823- or` |89 through the lower or reverse winding ofrelay IWR over contacts 2fand |64 toterminal C to neutralize or balance the effect of the current flowing. in the holding circuit eX- tending from terminal B at contact |88 or |89 through the upper or normal winding and contacts. |90 and4 I9I of. relay IWR, consequently relay IWR will release, opening its holding circuit. at contact` |9|, and opening the circuit for relay INC at contact |13, whereupon the circuit through the reverse winding of relay IWR will become,- effective to energize the relay so as to reverse contacts 86 and |89- and to again close contacts |89, IGI and |73, relay IRC becoming energized when the switch indication relay IWP becomes energized in the reverse direction as a result of the movement of the track switch to reverse.

It. follows that. in Fig. 3, relay |NC..or. I'RC,lde pending uponthe position. of contact 86; isnormally energized: andy these relays' by means of contacts |921 and |93 control the.. usual. normal and'. reverse switch. indication lamps INEl-and I RE` which are preferably mounted on the controlpanel.- ot'EiglG above the associatedswitch'. The. indication repeating relays .INWK

lever. and I RVJK in Fig. 3, however, are normally de,-

ofrelay INC, relay INWK, contact 84er" relay INR to `terminal C, and thereforecloses when* short or-in case-the relays WR are grouped-With aA route is setup requiring switch IA or IB to be normal as soon, as the switches assume the normal position in response to the energization of relay INR, and relay |NC becomes energized. As soon as the route is fully set up, relay ILS releases, and a connection to terminal C is closed over back contact 83 of relay` ILS so that relay I NWK remains energized after relay INR releases, until relay ILS is reenergized, precisely as in Fig. 1E, The rectifier |34 functions in an obvious manner to prevent relay INWK from being held energized over contact ISI of relay IWR. The circuit for relay IRWK is similar to that for INWK and it will be seen that these relays arranged as shown in Fig. 3 may be used for the same purposes as the corresponding relays of Fig. 1E.

Referring now to 4, it is often preferable to use a pair of interlocked neutral relays in place of a polar switch control relay and this view illustrates one manner by which this may be accomplished, In Fig. 4, relay IWNR is the normal and relay IWRR the reverse switch control relay, tliese relays controlling the switch machines in place of relay IWR by means of contacts ISS and |96, Relay IWNR is normally energized, as shown, over a circuit from terminal B, contact I8? and winding of relay IWNR, back contact |93 of relay IWRR, front contact |99 of relay IWNR to terminal C. If the route relay IRR is picked up or lever IP is moved to the right, a pick-up circuit for relay WRR is closed from terminal B, contact 82 of relay ILS, relay IWRR, rectier 200, contact |64 or |84 to terminal C. Relay IWRR picks up and at back contact |98 breaks the holding circuit for relay IWNR, and then relay IWNR releases and at its back contact |90 establishes a holding circuit for relay IWRR including its own front contacts 20| and |98. If now relay INR picks up or lever IP is moved to the left, a corresponding pick-up circuit for relay IWNR is closed over contact 83 of relay ILS and contact 84 or |84 and relay IWNR picks up and relay IWRR releases. Relay IWNR completes the circuit for relay INC at contact 202 and relay INC picks up to complete the circuit for relay INWK at contact 80 and for the normal indication lamp INE at contact IQZ. When relay ILS releases, relays IWNR and INC remain energized and a holding circuit is closed from terminal B at contact 89 of relay INC, the winding and front contact 203 of relay INWK, back contact |86 of relay ILS to terminal C, over which relay INWK is held energized after relay INR releases until relay ILS is reenergized. The circuits for relay IRWK in Fig, 4 are similar to those for relay INWK and it is clear that these relays may be used in place of the corresponding relays of Fig. 1E or Fig. 3.

Another novel feature of my invention is included in one form, in the route locking relay circuits'of Fig. 1D, and in an alternative form, in the circuits of Figs. 5A and 5B. This feature of my invention is an improvement upon that disclosed in a United States application, Serial No. 286,668 filed July 26, 1939, by G. L. Caille and A. P. Laze, for a Signalling and interlocking system for traffic routes, which corresponds with an application led in France on January 14, 1939. Heretofore it has been the practice to release the route locking relays for a route only Lwhen the route is established, for example, as hereinbefore explained in connection with the description of sett-ing up route fl--IZ in which case the series of relays AIES, 3ES and 'IES release successively in response to the opening of contact 97 of relay AIAS. In other words, it is the usual practice to arrange these relays so that they do not release unless a route is actually set up and often not unless the signal for a route has actually been cleared, and therefore the protection given by these relays is not available in the event a train passes over a route under other circumstances, as for example, with the apparatus in the normal position, as shown, or in fact, in any case when a train passes a signal which is at stopand its approach looking relay AS not deenergized. This limitation is overcome in accordance with my invention, as illustrated in Fig. 1D, by including in the stick circuits for those section locking relays associated with the entrance ends of routes having more than one track section, such as the relay AIES or 'IWS, a back contact such as the contact 204 or |00 of the other relay AIWS or IES for the same section. In the layout shown, this arrangement is required in the circuits for relays AIES, SES, 5WS and IWS only. It will be seen, therefore, that the stick circuits for these relays are normally open and that the section locking relays AIES, 3ES and 'IES for route 4|2 are released not only by deenergizing relay 4AS as a result of setting up route 4-I2 but also in the event a train moving from left to right passes signal 4 at stop and releases the track relay AITR. Likewise, if a train enters route 4-|2, or rather, route |24, from the right, the relays 'IWS, 3WS and AIWS are released successively by the opening of Contact 205 of relay 'ITR unless the switches are already locked due to the release of the ES relays. In either case, the relays LS of Fig. 1E will be released to lock the switches for the unoccupied sections in advance of the train to provide the desired protection against operation of these switches. On the other hand, the added back contacts do not interfere in any way with normal operation, for, as already explained, when a train moving from left to right enters route 4-I2, the ES relays will be released, relay 'IES closing at contact |00 the stick circuit for relay 'IWS to prevent its release by the opening of contact 205 of relay ITR, and similarly, for route |2-4, the closing of back contact 204 of relay AIWS prevents the release of relay AIES due to the opening of contact |48 of relay AITR by a train moving from right to left.

Figs. 5A and 5B illustrate another Way by which these desirable results may be obtained. Fig. 5A differs from Fig. 1D in that front contacts of the auxiliary directional relays E and W of Fig. 5B, such as contacts 206 and 2|I'I of relays 4W and IZE, are used in the stick circuits for the entering section relays of Fig. 5A in place pLthe back contacts 204 and |00 of relays AIWS and IES shown in Fig. 1D. This form of my invention differs further in that two of the relays, namely, relays AIWS and IES have been omitted. This is in accordance with the usual practice of omitting the section locking relays for the leaving sections of a route. Considering the train moving from left to right through route 4-I2, it will be apparent from Fig. 1E that contact II'I of relay "IES in the circuit for relay ILS may be replaced by a contact of relay 3ES to lock switch 'IB until the train enters section 1T, and that then switch 'IB will be locked by contact 208 of the track relay TTR.` Similarly, contact of relay AIWS in the circuit for revbe accomplished.

lay ILS may be replaced by a contactl of` relay sws.

Referring now to Fig. B, it will be seen that l an auxiliary relay E` or W is picked upwhen the signal control relay R for the entrance end of a route becomes energized to release the series of section locking relays for the corresponding direction. Thus considering route 4-I2, for eX- ample, when relay 4R picks up, a circuitisclosed from terminal B, front contact 209 of relay 4R, front contacts 2I0 to 2| 3, inclusive, of the relays NWK for route d-IZ, relay IZE to terminal C. When the train passes signal i and enters section AIT, relay 4R releases, but relay ISE is held energized over a stick circuit extending from terminal B, back contact 2-I4 of relay AITR, front contact 215 of relay INWK, back contacts 2I6 and 2H of relays ERWK and 'IRWK, the front contact 2I3 and Winding of relay I 2E to terminal C. As the train advances, additional connections from terminal B to the stick circuit for relay IIE are provided at contacts 2I9 and 220 of relays STR and ITR to hold relay IZE energized, so that Contact 281, Fig. 5A, will be held closed'as long as the front contact 2050i relay TTR in the circuit for relay 'IWS is open, to prevent the release of relay lWS by a train moving from left to right. For the opposite direction, relay 4W has a pick-up circuit extending from terminal B at contact 22I of relay I2R over contacts 222 to 225, inclusive, of the NWK relays through relay 4W to terminal C, and a stick circuit extending to terminal B over each of the back contacts 225, 221 and 228 of relays TTR, STR and AITR, and contact 2iJB'of relay 4W in Fig. 5A therefore functions so as to prevent the release of relay AIES due to the opening of contact |138 of relay AITR by a train moving from right to left. It will be seen, therefore, that the circuits of Figs. 5A and 5B function in the desired manner to lock the track switches in sections in advance of a train irrespective of whether the signal control relay R has been picked up or not.

Heretofore in systems of this character, as illustrated for example by the disclosures of each of the patents and applications hereinbefore referred to, it has been customary to employ two normal route relays for each crossover, one for each of the two parallel routes rendered available when the crossover switches are normal, instead of a single relay such as the relay SNR of Fig. 1B. While the arrangement of Fig. 1B is to be preferred on account of the saving in relays, the older arrangement of the relays may be preferred under certainconditions and may also be used with the circuits of my invention.

Fig. 6 illustrates one manner by which this may It will be seen that in Fig. 6 the contacts and their connections are substantially identical with those of Fig. 1B except that a pair of relays such as the relays EANR and SBNR replaces each normal crossover relay such as relay ENR, the rectiers 6I and Ela which in Fig. 1B permit relay BNR to be energized over either of two independent circuits Without interference have been omitted, contacts 229 and 230 of relays SANR and EBNR, respectively, replacingcontacts IM and 62 of relay ENR, The circuit operation in Fig. 6 is identical with that of Fig. 1B, and a detailed explanation appears unnecessary, likewise the manner in which these relays may be employed in connection with the circuits of Figs. v1A and k1E appears to be self .evi-

dent.'

Although I have herein shown and described only one form of apparatus embodying my invention and five modifications of portions thereof, it is understood that various changes and modications may be made therein within the scope of the appended claims Without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. In an interlocking control system, a track layout includingtrack switches adapted to be arranged to form diierent routes for traflicmovements in two directions, route levers for the' ends of said routes each having a normal position andr two control positions, an entrance relay for each route entrance and an exit relay for each route exit in said layout, normal and reverse route relays for governing the operation of the track switches to their normal and reverse positions, means for energizing the entrance and exit relays for the two ends of a selected route when the route levers for the ends of said route are successively operated to corresponding positions, a single route circuit network comprising conductors arranged to correspond with the tracks of said layout interconnected by movable `contacts located at points corresponding to the locations of the track switches, said vnetwork comprisinga route circuit for each route controlled by the eXit relay for one end or the other dependentupon s the tranic direction to be established, means 'controlled by each entrance relay when energized for operating one or more ofsaid movable contacts as required to isolate the route circuits controlled by such relay from those for conflicting routes having different entrance ends, means compris-l ing the route circuit for a selected route having its entrance and exit relays energized for energizing said route relays as required to establish said route for traic movements in either direction, and means controlled by said energized route relays for operating certain of said movable contacts as required to isolate said energized route circuit from the circuits for conflicting routes having different exit ends.

2. In an interlocking control system, a track layoutincluding track switches adapted to bearranged to form different routes for governing traffic in two directions, an entrance relay and an exit relay for each route end, manually operable means for successively energizing the entranceY and exit relays for the opposite ends of a selected route, normal andreverse route relays for governing the operation of the track switches to their normal and reverse positions, a single route circuit network including a circuit for each route through the layout for energizing selected route relays as required to establish such route for traffic movements in either direction, means governed by the entrance relay for a selected route when energized for isolating the route circuit for such route from the circuits for conflicting routes having the same exit end, means governed' by the eXit relay for the selected route when energizedfor energizing the route circuit for such route at one end or the other dependent upon which traffic direction is to be established, to operate the route relays as required to establish the selected route, and means governed by said energizedV` route relays for isolating said energized route'circuit from the circuits for' all coniiictingroutes.

3. In an interlocking control system, a track layout including track switches arranged to'form different routes for governing traflic in twoxdi rections, an entrance relay and .an= exit relays and a route lever for each route end, means responsive to the operation of the lever for the entrance end of a route for energizing the corresponding entrance relay, a route selecting network for each direction each including a selecting circuit for each route for the corresponding direction prepared by energizing the entrance relay and completed by energizing the exit relay for such route, said network including contacts so controlled by the entrance relays as to prevent the energization of selecting circuits for routes having portions in common, by more than one entrance relay at a time; means responsive to the operation of the lever for the exit end of a route having its selecting circuit prepared for energizing the exit relay for such route, normal and reverse route relays for governing the operation of the track switches to their normal and reverse positions, a non-directional circuit network including a circuit for each route controlled by the exit relays for the opposite ends of such route for energizing selected route relays as required to establish the route for traic movements in a direction dependent upon whi-ch of the two exit relays associated with opposite directions of trafc movements over such route is energized, and means governed by the energized route relays for isolating the circuits for the selected route from the circuits for all conflicting routes.

4. In an interlocking control system, a track layout including track switches arranged to form different routes for governing traic in two directions, an entrance relay and an exit relay for each route end, manually operable means for successively energizing the entrance and exit relays for the opposite ends of a selected route, a route selecting circuit network for each direction including a selecting circuit for each route for the corresponding direction, means controlled by each entrance relay when energized for preparing the selecting circuit for each route having the corresponding entrance point, means responsive to the energization of an exit relay for the exit end of a route having its selecting circuit prepared for maintaining such exit relay energized over said prepared circuit under the control of the energized entrance relay, normal and reverse route relays for governing the operation of the track switches to their normal and reverse positions, a non-directional circuit network including a circuit for each route controlled by the entrance and exit relays for the opposite ends of such route irrespective of the trafiic direction to be established, each such circuit having a branch including the winding of the normal or reverse route relay for each switch of the corresponding route, and means governed by the energized route relays for isolating the circuits for the selected route from the circuits for all conflicting routes.

5. In an interlocking control system, a track layout including track switches arranged to form different routes for governing traic in two directions, an entrance relay and an exit relay for each route end, manually operable means for successively energizing the entrance and exit relays for the opposite ends of a selected route, a route selecting circuit for each route for the corresponding direction, means controlled 4by each entrance relay when energized for preparing the selecting circuit for each route having the corresponding entrance point, means responsive to the energization of an exit relay for the exit end of a route having its selecting circuit prepared for maintaining such exit relay energized over said prepared circuit under the control of the ener- 75 gized entrance relay, normal and reverse route relays for governing the operation of the tra-ck switches to their normal and reverse positions, a non-directional route circuit network including a route circuit for each route, means controlledv 6. In an interlocking control system, a trackA layout including track switches arranged to form different routes for governing tranic in two directions, an entrance relay and an exit relay for each route end, manually operable means for successively energizing the entrance and exit relays for the opposite ends of a selected route, a route selecting circuit network for each direction including a selecting circuit for each route ior the corresponding direction, means controlled by each entrance relay when energized for preparing the selecting circuit for each route having the corresponding entrance point, means responsive to the energization oi an exit relay for the exit end of a route having its selecting circuit prepared for maintaining such exit relay energized over said prepared circuit under the control of the energized entrance relay, a plurality of selecting relays controlled by said entrance relays over said selecting circuits, contacts controlled by said entrance relays and said selecting relays eiective to prevent the control of any exit relay by more than one entrance relay at a time, normal and reverse route relays for governing the operation of the track switches to their normal and reverse positions, a non-directional circuit network including a route circuit for each route, means controlled by each entrance relay when energized and by the selecting relays controlled by such entrance relay for preparing the route circuit for each route having the corresponding entrance point, means controlled by each eXit relay when energized for completing the route circuit for the route having the corresponding exit point, means including the completed route circuit for energizing the route relays as required to establish such route, land means governed by the energized route relays for isolating the selecting circuit and the route circuit for the selected route from the circuitv for conflicting routes until the exit relay for such route is released.

7. In an interlocking control system, a track layout including track switches adapted to be arranged to lorm different tratc routes, route levers for the ends of said routes each having a normal position and two control positions, a pair of stick relays for each route including an entrance relay and an exit relay for each route end, means for energizing the entrance relay at one end and the eXit relay for the other end of a route when the two levers for the ends of said route are successively operated to one control position, means or energizing the entrance relayA for said other end and the exit relay for said one end of said route when the two levers for the end of said route are successively operated to their other position, a stick circuit for each entrance relay including a back contact of the.

exit relay for the same route end, a stick circuit for each exit relay controlled by a front contact of the entrance relay for the other end of the same route, switch control means controlled by the exit relays for a route for operating the track switches as required to establish such route, a signal at each end of each route for governing the movement of trailic over the route, a signal control relay for each route end, a circuit including a front Contact of the energized exit relay for a route for energizing the signal control relay for the entrance end of such route when the track switches assume the positions required for such route, and means controlled by each switch control relay when energized for rst locking each track switch of the route in the required position and for then clearing the signal at the entrance end of such route.

8. In an interlocking control system, a trac1 layout including track switches adapted to form dierent routes for governing trafic movements in two directions, an entrance relay and an exit relay for each route end, manually operable means for successively energizing the entrance and eXit relays for the opposite ends of a selected route, switch control means controlled by the entrance and exit relays for a route for operating the track switches as required to establish such route, signals vat the ends of the routes for governing traffic movements over the route in opposite directions, a signal control relay for veach route end, a circuit including a front contact of the energized exit relay for energizing the signal control relay for the entrance end of the corresponding route when each track switch of' the route assumes the position required to establish the route, and va signal circuit for clearing the signal at the entrance end of said route including front contacts of said signal control relay and contacts controlled by each track switch of the established route.

9. In an interlocking control system, a track layout including a plurality of track sections containing track switches which may be arranged to form different trac routes, manually operable devices for selecting said routes, a locking relay for each section energized only when conditions are proper for the operation of the switch in such section, normal and reverse route relays -for each switch, means controlled by each route relay for operating the corresponding switch to Aits normal or reverse position eiective only when the locking relay for that switch is energized, normally deenergized normal and reverse indication relays for each switch, means for energizing each such normal or reverse indication relay when the normal or reverse route relay for the same switch is energized and the switch assumes the corresponding normal or reverse position, route selecting circuits for governing the operation of said route relays as required t0 establish the route selected by the operation of said manually operable devices, means for isolating the route selecting circuits for established routes from those for conflict-ing `routes comprising a back contact of each normal indication relay in a circuit governing the associated reverse route relay, and a back contact of each reverse indication relay in a circuit governing the associated normal route relay, means for releasing the locking relay for each switch of a selected route when such route is established, and means controlled by each such locking relay when released for maintaining energized the normal or reverse indication relay for the associated switch to maintain the corresponding route selecting circuit isolated only until such locking relay is again energized.

10. In an interlocking control system, a track layout including a track switch operable to normal and reverse positions to form diierent traffic routes, route levers for selecting said routes, normal and reverse route relays for governing the operation of the track switch to said normal and reverse positions, normally deenergized normal and reverse indication relays, means for energizing the normal or reverse indication relay when the normal or reverse route relay is energized and the switch assumes the corresponding normal or reverse position, route selecting circuits controlled by said route levers for governing the operation of said route relays to selectively establish said routes, and means controlled by said indication relays for interlocking said selecting circuits comprising a back contact in each selecting circuit which opens when the indication relay controlled by the'route relay for the other selecting circuit is energized.

l1. In an interlocking control system, a track layout including a track switch operable to normal and reverse positions to form diierent trafc routes, route levers for selecting said routes, normal and reverse route relays for governing the operation of the track switch .to said normal and reverse positions, normal and reverse indication relays, means for energizing the normal or reverse indication relay when the normal c-r reverse route relay is energized and the switch assumes the corresponding normal or reverse position, route selecting circuitsincluding selecting relays energized in response to the operation of said route levers for governing said route relays to selectively establish said routes, means for interlocking said selecting circuits comprising back contacts of a route relay and Yof an indication relay in series in each of said selecting circuits, f

the contacts in each circuit being controlled by the relays governed by the other circuit, and means for deenergizing said energized route and indication relays to permit one selecting circuit or the other to be energized.

12. In an interlockingcontrol system, a track section including a track switch operable to normal and reverse positions to form di'lerent tramo routes, route levers for selecting said routes, a locking relay energized only vwhen said track section is unoccupied and conditions are proper for operating the track switch, normal and reverse route relays each effective when said locking relay is energized to govern the operation of the track switch to a corresponding normal or reverse position, normal and reverse indication relays, means for energizing the normal or reverse indicationv relay when the normal orreverse route relay is energized and the switch assumes the corresponding normal or reverse position, route selecting circuits controlled by said route levers for governing said route relays to selectively establish said routes, each selecting circuit including in series back contacts of the route relay governed 'by the other selecting circuit and of the indication relay controlled thereby, and means eiective when a route has been established and said locking relay has been released to maintain the energized indication relay picked up until said locking relay is again energized, Airrespective of the condition of the corresponding route relay.

13. In an interlocking control system, a track layout including a' trame route having a first portion extending from the entrance end of the 'lay- 

